sh: Split out the unaligned counters and user bits.

This splits out the unaligned access counters and userspace bits in to
their own generic interface, which will allow them to be wired up on sh64
too.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 160 insertions, 1 deletions

diff --git a/arch/sh/mm/Makefile b/arch/sh/mm/Makefile
index dd5010c708e0..9fa11d655044 100644
--- a/arch/sh/mm/Makefile
+++ b/arch/sh/mm/Makefile
@@ -2,7 +2,7 @@
 # Makefile for the Linux SuperH-specific parts of the memory manager.
 #
 
-obj-y                   := cache.o init.o consistent.o mmap.o
+obj-y                   := alignment.o cache.o init.o consistent.o mmap.o
 
 cacheops-$(CONFIG_CPU_SH2)              := cache-sh2.o
 cacheops-$(CONFIG_CPU_SH2A)             := cache-sh2a.o
diff --git a/arch/sh/mm/alignment.c b/arch/sh/mm/alignment.c
new file mode 100644
index 000000000000..e615151eac3b
--- /dev/null
+++ b/arch/sh/mm/alignment.c
@@ -0,0 +1,159 @@
+/*
+ * Alignment access counters and corresponding user-space interfaces.
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Copyright (C) 2009 - 2010 Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/uaccess.h>
+#include <asm/alignment.h>
+
+static unsigned long se_user;
+static unsigned long se_sys;
+static unsigned long se_half;
+static unsigned long se_word;
+static unsigned long se_dword;
+static unsigned long se_multi;
+/* bitfield: 1: warn 2: fixup 4: signal -> combinations 2|4 && 1|2|4 are not
+   valid! */
+static int se_usermode = UM_WARN | UM_FIXUP;
+/* 0: no warning 1: print a warning message, disabled by default */
+static int se_kernmode_warn;
+
+void inc_unaligned_byte_access(void)
+{
+        se_half++;
+}
+
+void inc_unaligned_word_access(void)
+{
+        se_word++;
+}
+
+void inc_unaligned_dword_access(void)
+{
+        se_dword++;
+}
+
+void inc_unaligned_multi_access(void)
+{
+        se_multi++;
+}
+
+void inc_unaligned_user_access(void)
+{
+        se_user++;
+}
+
+void inc_unaligned_kernel_access(void)
+{
+        se_sys++;
+}
+
+unsigned int unaligned_user_action(void)
+{
+        return se_usermode;
+}
+
+void unaligned_fixups_notify(struct task_struct *tsk, insn_size_t insn,
+                             struct pt_regs *regs)
+{
+        if (user_mode(regs) && (se_usermode & UM_WARN) && printk_ratelimit())
+                pr_notice("Fixing up unaligned userspace access "
+                          "in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
+                          tsk->comm, task_pid_nr(tsk),
+                          (void *)regs->pc, insn);
+        else if (se_kernmode_warn && printk_ratelimit())
+                pr_notice("Fixing up unaligned kernel access "
+                          "in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
+                          tsk->comm, task_pid_nr(tsk),
+                          (void *)regs->pc, insn);
+}
+
+static const char *se_usermode_action[] = {
+        "ignored",
+        "warn",
+        "fixup",
+        "fixup+warn",
+        "signal",
+        "signal+warn"
+};
+
+static int alignment_proc_show(struct seq_file *m, void *v)
+{
+        seq_printf(m, "User:\t\t%lu\n", se_user);
+        seq_printf(m, "System:\t\t%lu\n", se_sys);
+        seq_printf(m, "Half:\t\t%lu\n", se_half);
+        seq_printf(m, "Word:\t\t%lu\n", se_word);
+        seq_printf(m, "DWord:\t\t%lu\n", se_dword);
+        seq_printf(m, "Multi:\t\t%lu\n", se_multi);
+        seq_printf(m, "User faults:\t%i (%s)\n", se_usermode,
+                        se_usermode_action[se_usermode]);
+        seq_printf(m, "Kernel faults:\t%i (fixup%s)\n", se_kernmode_warn,
+                        se_kernmode_warn ? "+warn" : "");
+        return 0;
+}
+
+static int alignment_proc_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, alignment_proc_show, NULL);
+}
+
+static ssize_t alignment_proc_write(struct file *file,
+                const char __user *buffer, size_t count, loff_t *pos)
+{
+        int *data = PDE(file->f_path.dentry->d_inode)->data;
+        char mode;
+
+        if (count > 0) {
+                if (get_user(mode, buffer))
+                        return -EFAULT;
+                if (mode >= '0' && mode <= '5')
+                        *data = mode - '0';
+        }
+        return count;
+}
+
+static const struct file_operations alignment_proc_fops = {
+        .owner          = THIS_MODULE,
+        .open           = alignment_proc_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+        .write          = alignment_proc_write,
+};
+
+/*
+ * This needs to be done after sysctl_init, otherwise sys/ will be
+ * overwritten.  Actually, this shouldn't be in sys/ at all since
+ * it isn't a sysctl, and it doesn't contain sysctl information.
+ * We now locate it in /proc/cpu/alignment instead.
+ */
+static int __init alignment_init(void)
+{
+        struct proc_dir_entry *dir, *res;
+
+        dir = proc_mkdir("cpu", NULL);
+        if (!dir)
+                return -ENOMEM;
+
+        res = proc_create_data("alignment", S_IWUSR | S_IRUGO, dir,
+                               &alignment_proc_fops, &se_usermode);
+        if (!res)
+                return -ENOMEM;
+
+        res = proc_create_data("kernel_alignment", S_IWUSR | S_IRUGO, dir,
+                               &alignment_proc_fops, &se_kernmode_warn);
+        if (!res)
+                return -ENOMEM;
+
+        return 0;
+}
+fs_initcall(alignment_init);